Questions tagged [c]

The C programming language: its historical aspects and use on/targetting retro platforms.

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32 votes
6 answers
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In the ISO 1990 C standard library, what was the rationale for having memcpy return one of its inputs?

The function memcpy is defined as: void* memcpy(void* s1, void* s2, size_t n) and the 1990 ISO standard (ISO 9899:1990) defines the function as: Description The memcpy function copies n characters ...
16 votes
1 answer
3k views

In P.J. Plauger's "The Standard C Library" (1992), why are for loops used so frequently instead of while loops in the implementations?

I think I'm getting into such a specific question that there may be no answer, but it seems curious to me. This is a retrocomputing question, I promise, see the last paragraph to see how. In Plauger's ...
1 vote
0 answers
140 views

DirectX 8 Win32 GUI Not Appearing/Flickering While Running [closed]

I am programming a game with DirectX 8, and I am trying to use the GUI options that are provided by the Win32 window that I am using. However, when I try to render a button or, in this case, a textbox ...
52 votes
5 answers
16k views

Why did C have the return type before function names?

In general, there are two types of syntax of defining functions - Something like C, C++, C#, or Java (int functionName(char arg)) vs the ML (and others) tradition of defining the return type after the ...
90 votes
20 answers
19k views

Have programming languages driven hardware development?

Programming language development has been influenced by hardware design. One example from this answer mentions how C pointers were, at least in part, influenced by the design of the PDP-11. Has the ...
13 votes
10 answers
2k views

Alternatives for TurboVision on DOS

TurboVision was a library by Borland for developing TUI's (Text User Interfaces). It was included with their C++ and Pascal compilers. Were there any other TUI libraries that supported multiple ...
9 votes
2 answers
549 views

Which linker or object-file format imposed the 6-character restriction on external names?

It's my understanding that the reason that external identifiers in portable C programs had (still have?) to be unique in the first six characters is that six 6-bit characters¹ fill a 36-bit machine ...
11 votes
3 answers
1k views

Are there architectures with alignment greater than the size of machine word in the pre-32-bit era?

I'm writing a hobbyist cryptography project, and I want to ensure the data structures I define don't have padding bytes. The only assumption I've made about the environment, is that bytes are exactly ...
40 votes
4 answers
6k views

When was this C function definition style, with type declarations of parameters after the parameter list, invented?

Recently I dug a little bit into old graphics libraries and found libxmi. The site was last updated on 08/09/2000. And in the source code I found the following style of function definitions which I ...
72 votes
5 answers
16k views

Why did C use the arrow (->) operator instead of reusing the dot (.) operator?

In the C programming language, the syntax to access the member of a structure is structure.member However, a member of a structure referenced by a pointer is written as pointer->member ...
16 votes
3 answers
1k views

Are there any public tools for the TMS34010?

I am interested to learn about the Texas Instruments TMS34010, a 32-bit fully functional CPU with built-in graphics manipulation capabilities, which appeared in Atari's Hard Drivin' arcade boards ...
38 votes
6 answers
7k views

Why couldn't early C compilers handle variable declarations between statements?

In modern C, you may place variable declarations between statements: do_something(); int x; x = something_else(); However, older C compilers required that variables are declared before all statements:...
2 votes
1 answer
131 views

CC65 ignores request to correctly offset memory areas in output files

I'm trying to segment my C code into two distinct memory areas, one which will be flashed to a ROM chip and another which will end up somewhere else. Here is what I have in sbc.cfg (I was originally ...
24 votes
11 answers
10k views

Why weren't 80s arcade games programmed in C?

I know many arcade games from the 80s were programmed in 68000 assembly. This carried on probably well into the 90s, even though Motorola C compilers existed in the 80s. Why then weren't C compilers ...
26 votes
9 answers
5k views

How common was programming in C targeting 8-bit processors in 1983?

How often was C used to program firmware for 8-bit processors in the early 80s? I'm reverse engineering a firmware binary for a device built around a Hitachi 6303 processor, manufactured in 1983. Even ...
14 votes
1 answer
2k views

How can I set up the Microsoft C compiler to make it prefer immediate-mode push instructions?

I started a project to get a better understanding on how to compile a game for Windows 3.x. I tried to set up the build workflow so that it produce the byte-exact clone of a great open sourced Win16 ...
3 votes
1 answer
172 views

How to remove ___EXPORTEDSTUB statement from a NE (Win16) program's MAP?

I started a project to get a better understanding on how to compile a game for Windows 3.x. I tried to set up the build workflow so that it produce the byte-exact clone of a great open sourced Win16 ...
-2 votes
2 answers
324 views

1980s version of printf in C [closed]

In a well-known article by Ken Thompson, ( http://users.ece.cmu.edu/~ganger/712.fall02/papers/p761-thompson.pdf ) in figure 1, that formats printf with decimal %d printf("\t%d, \n", s[i]); ...
9 votes
1 answer
533 views

Which pre-ANSI C compilers allowed a conditional expression as Lvalue?

Soon after learning the C language in the late 80s, before an ANSI C compiler was available on the machines I was using, it occurred to me to check if the following compiles int a, b, c; foo() { (...
11 votes
3 answers
4k views

How can I create a pipe for stdin/stdout of command.com (or 4dos.com) in C or a batch file?

I'm working on a retro project and was trying to create a pipe of stdin/out/err in DOS, but I can't find any functions to to this. For instance the pipe() function from unistd.h isn't present in ...
47 votes
3 answers
5k views

How did varargs in C develop?

C has a feature for variadic functions, my understanding is this feature was originally a hack, relying on the simple stack-based parameter passing used by early C implementations and that some time ...
19 votes
10 answers
7k views

When if ever was the C language 'int' size altered from the host machine word (register) size into a literal 32 bit size?

From the earliest K&R reference manuals I read, 'int' was synonymous with machine word and it seemed to raise adverse reactions in various user domains. With the UNIX crowd, they minimally ...
15 votes
1 answer
2k views

How would old software using the SIGPIPE signal really work if it were to manage _many_ pipes?

I'm wondering what was the thinking behind having a SIGPIPE signal. From my own experience, the first thing I do is turn off that signal (SIGIGN) and use the return value of the calls to make sure it ...
50 votes
2 answers
24k views

Why were the /\ (min) and the \/ (max) operators abandoned in the C language?

In the UNIX V7 version of the C language (but not yet in the V6 version), there were the /\ (min) and the \/ (max) operators. In the source of the scanner part of the compiler, case BSLASH: if (...
58 votes
4 answers
11k views

Why were single quotes ('…') chosen for characters, and double quotes ("…") for strings?

In C, '' is used to denote a character, while "" is used to denote a string. Why was this syntax chosen? I tried to research this using Wikipedia’s Timeline of Programming Languages along ...
19 votes
0 answers
1k views

Oxford C compiler for Commodore 64

I kept one floppy from my Commodore 128 (which I used mostly in C64 mode), labelled ‘Oxford C compiler’. It is a 5.25″ floppy. Don't ask me why I kept just this one; probably because I thought I ...
20 votes
3 answers
6k views

Native C compiler for Sinclair ZX Spectrum

I am looking for a native C compiler for the Spectrum 128. I would like one which: Has good support for the latest C standard at the time. Is not limited to compiling ridiculously short source code. ...
8 votes
2 answers
743 views

How can I malloc() a block that's guaranteed to lie within a single DMA segment in Turbo C 2.01?

I'm following root42's videos about DOS programming using Turbo C 2.01. I've written my own Soundblaster 1.xx driver following the Creative Labs documentation, and I'm confused about memory allocation....
98 votes
9 answers
38k views

Why do C to Z80 compilers produce poor code?

When reading some other questions about compiling C for the Z80, How much benefit should be expected on a more advanced compiler for z80/r800 based computers? Native C compiler for Sinclair ZX ...
2 votes
1 answer
194 views

Where can I find the software for "DESIGN: a program to create data entry programs" by J. Michael Wuerth?

I have a copy of the book, DESIGN: a program to create data entry programs by J. Michael Wuerth. Does anyone know where I can obtain a copy of the accompanying software for the book?
6 votes
4 answers
836 views

C/C++ UI library similar to Visual Basic for DOS

I'm looking for a UI library that offers a similar "experience" to that provided by Microsoft's infamous, Visual Basic for DOS RAD environment. I mean, it's such a compelling environment, ...
1 vote
1 answer
344 views

Did DEMOS have a C compiler?

DEMOS was a Soviet operating system derived from BSD Unix. The answer to this question shows that the familiar, English-derived BSD commands were essentially the same in DEMOS. Did DEMOS have a C ...
14 votes
2 answers
2k views

How would I reliably detect the amount of RAM, including Fast RAM?

If I was to write an Amiga game, what would be the best/most reliable way to detect how much RAM is actually available? Looking at Action's Guide to AGA-Fixing!, he mentions Faulty Memory Detection: ...
2 votes
1 answer
313 views

Microsoft C 6, far pointer, cast to int, warning C4047

Trying to access one byte in memory using segment/offset, like this union REGS in, out; struct SEGS segs; int v; char _far* p; ... int86x(...,&in,&out,&segs); p = (segs.es << 16) + ...
26 votes
1 answer
4k views

Where is the ancient preprocessor?

I found the old C compiler from V6, and, though it seems to the modern eye a little different from good, idiomatic C, evidently it uses things like #include and #define, but I do not see how it ...
7 votes
2 answers
647 views

Labels in cc65 inline assembler with #define macro

In general, it is possible to use inline assembler statements within C macros, for example #define toscreencode(C) (__AX__ = (C), \ asm("cmp #$60"),\ ...
1 vote
1 answer
216 views

When did cross-platform C start assuming function prototypes? [closed]

The most important difference between the original 'K&R' C, and ANSI/ISO C89/90, was function prototypes. These started being supported by some compilers in the mid-eighties, were formally ...
3 votes
2 answers
399 views

How to implement a 'write' function in pdp-11 / MACRO-11 / ODT using simh?

So, I'm working on a project where I'm aiming to get the first winner of the IOCCC (obfuscated c code contest) dissected down to the last detail... The program is mullender.c which you can find by ...
32 votes
2 answers
8k views

Which tools were used to create the C language?

Was the original C compiler written in some old assembly language and now later flex and bison are used instead?
9 votes
1 answer
1k views

What was the name of the object-oriented C language I used in the 1980s on the Mac

I clearly recall working with an object-oriented C derivative on the Mac but I cannot find any definitive references to it. It was back in the days of System 7 and later System 8. It had both ...
31 votes
3 answers
4k views

Why is the ‘auto’ storage class specifier included in C?

The auto keyword in C seems quite redundant: wherever it makes sense to define a variable with automatic storage duration, it is already the default, so there is no reason to use the keyword. The ...
36 votes
6 answers
5k views

Why is this gcd implementation from the 80s so complicated?

First of all, I hope this is the right place to post this question. I was looking through one of my dad's old programming books from the 80s, and at the back it has a list of utility functions, one of ...
19 votes
6 answers
4k views

What caused the downfall of Pascal? [closed]

From 1985 to 1990 Borland's Turbo Pascal was at least as popular as C for DOS systems. Turbo Pascal was especially popular because of it's ground breaking BGI graphics interface while C was stalled in ...
36 votes
5 answers
9k views

Why (historically) include the number of arguments (argc) as a parameter of main?

A comment on this answer to a StackOverflow question made me curious. According the C99 standard, section 5.1.2.2.1: The function called at program startup is named main. The implementation ...
6 votes
3 answers
1k views

Allocate 64 KiB in Watcom C 16-bit DOS

I'm trying to allocate a 64 KiB buffer in Watcom C 16-bit DOS. I'm using the "compact" memory model which defines the code segment to be limited to 64 KiB and addressed by near pointers (...
11 votes
3 answers
2k views

Is this the reason why fread/fwrite has 2 `size_t` arguments?

It just came to me that, the C standard I/O functions fread and fwrite are having 2 size_t arguments because of I guess possibly, that on some systems, there may be more memory of which whose size can ...
2 votes
2 answers
253 views

Why isn't this invocation of XMS function Move EMB 0Bh in Turbo C correct?

Following on from my last question, I cannot get Move Extended Memory Block (Function 0Bh) working in Turbo C 2.01. The following main.c contains only the minimum functions: get the XMS driver pointer,...
0 votes
3 answers
298 views

Should C be regarded as an Intermediate Language? [closed]

Should C be regarded as an intermediate language on a virtual machine named PDP-11 Architecture (which have a plain memory space and stacks), like opcode to jvm, msil to dotnet, asm.js to v8, which ...
1 vote
1 answer
268 views

Working on programming a retro z80 computer (SDCC error)

I am working on coding a driver of sorts for a Z80 based computer I am making. I am compiling with SDCC and I have been getting the following? ASlink-Warning-Undefined Global 'data' referenced by ...
2 votes
0 answers
189 views

Hitting the CMS Limits of Portable Code

I wrote this arbitrary precision arithmetic utility on BSD in my postgraduate days, then after graduating ported it to DOS using TurboC. Was proud that it would do the same thing with 16bit word ...